The invention relates to a balloon control ring for a textile machine for limiting a circulating yarn balloon, and more particularly wherein the balloon control ring comprises a metallic hollow cylinder with a wear-resistant surface.
So-called balloon control rings are used on two-for-one twisters and ply twisters in order to restrict the circulating yarn balloon formed by the running yarn. At winding machines, the balloon behavior of the yarn drawn from the cop is also influenced by means of the balloon control ring and the yarn tension is kept low.
The use of balloon control rings allows a reduction in the spacing designated the spindle gauge from spindle centre to spindle centre. In this manner, more spindles can be arranged at a textile machine without lengthening the machine.
German Patent Publication DE 1510869 A shows a balloon control ring, the cylindrical shell of which is formed by a ring. The holding takes place by means of solid filler elements which surround the balloon control ring on the entire periphery. The filler elements are in each case fastened to one of two longitudinal profile carriers extending spaced apart. This holding is expensive. The ring has folded over portions to secure its position, which prevent falling from the filler elements. Rings of this type are produced by forming methods such as extrusion or by welding.
It is known, for example, from German Patent Publication DE 2941160 A1, to produce the balloon control ring from formed aluminium or nickel chromium sheet metal. A hollow body produced by extrusion provides the running yarn with a disruption-free circulating path.
A straight bead-welded tube made of rolled sheet metal which is provided with a weld seam at the joint edge and is then pressure-rolled presents an economical finished hollow body for balloon control rings. Designs of this type require relatively thick sheet metal to ensure the stability of the balloon control ring. A sheet metal thickness of this type is also necessary for manufacturing reasons in order to be able to produce the balloon control ring as a deep-drawn part or in order to be able to lay a weld seam.
It is known from German Patent Publication DE 1510844 A to use wear-reducing special steels for balloon control rings, which special steels are however too heavy and too expensive. To avoid this drawback, it is proposed to form solid balloon control rings from aluminium alloys or balloon control rings from foils made of any material and to provide the inner surfaces of the balloon control rings with a chemically applied deposit of a phosphor alloy based on chromium as well as nickel, the hardness of which is at least equal to the hardness of a normal anodising layer of a balloon control ring made of an aluminium alloy. Balloon control rings which comprise foil strips made of metal or plastics material, however, have inadequate dimensional stability.